This invention relates to a honeycomb member for a honeycomb core or panel. By using a single honeycomb member or by the arrangement of multiple honeycomb members, a honeycomb core or panel can be formed.
Typically, a honeycomb core is composed of a plurality of dense close ended cells and can be used as core material for a flat honeycomb panel. The cells typically have a hexagonal or square cross section. When a honeycomb core or panel is used for various structural applications, curved configurations are often required. A curved honeycomb core or panel is generally manufactured by merely bending plate material, but other known methods for manufacturing a curved honeycomb core or panel also exist and are now explained.
As shown in FIG. 9, flexible honeycomb core members composed of cells defined by curved faces are manufactured. The honeycomb core members are then adhered, soldered or welded to one another along a desired curvature to form a honeycomb core.
A second known method, shown in FIG. 10, depicts a plurality of strip materials 101 which are bonded together by applying adhesive onto hatched portions 102 and then formed into a lamination 103. After a crosshatched portion 104 is removed from the lamination 103, the lamination 103 is extended to form a curved honeycomb core 105. The curved honeycomb core 105 is then sandwiched and bonded between face plates 106 and 107 to produce a curved honeycomb panel.
Japanese Laid-Open Patent Publication No. 58-25531 discloses another method as shown in FIGS. 11A through 11D. A strip material 111 is folded along folding lines 112 and 113. As shown in FIG. 11A, the folding lines 112 are perpendicular to a center line CL, and the folding lines 113 are slanted in relation to the center line CL. The strip material 111 is then folded along the folding lines 112 and 113 to form a corrugated sheet 116. As shown in FIGS. 11B and 11C, the corrugated sheet 116 has inclined ridges 114 and grooves 115. As shown in FIG. 11D, when the corrugated sheet 116 is overlapped with one another corrugated sheet, the ridges 114 of one corrugated sheet 116 are attached onto the grooves 115 of another corrugated sheet 116 through spot welding, thereby defining hexagonal cells 118 thus creating a curved honeycomb core 117.
The aforementioned related-art methods for manufacturing curved honeycomb cores or panels have many problems. In the first-explained related-art method, when a curved honeycomb core is manufactured by bending the plate material, the honeycomb core resists against the force required to bend it, thus permitting only large radii of curvature. Small radii of curvature cannot be obtained, using this method.
In the second related-art method shown in FIG. 9, the materials of the honeycomb cores have such a special configuration that positioning of the materials for forming cells is troublesome when the honeycomb cores are laminated onto one another. The production time is thereby significantly increased, moreover, the desired honeycomb core becomes more difficult to form as its height increases, due to the required curvature.
The second related-art method, shown in FIG. 10, involves multiple process steps, which increase production time. Furthermore, the honeycomb core 105 is not adequately supported perpendicular to its defined curvature, therefore the honeycomb panel produced has insufficient strength.
In the last related-art method shown in FIGS. 11A through 11D, it is difficult to form the corrugated sheet 116 by folding the strip material 111 along the folding lines 112 and 113. It is also troublesome to form the cells 118 having hexagonal cross section by positioning and attaching the corrugated sheets 116. Additionally, the corrugated sheets 116 are bent with only a limited radius of curvature. This method, as defined, is insufficient to provide honeycomb cores or panels having varying radii of curvature.